Names need decoration (stdcall) in order to be linked.
When using the wsk.h header functions exported therein should
be WSKAPI (which enforces the stdcall calling convention). Linking
would later fail because stdcall functions are named differently in
the object code.
Some datagram related dispatcher function types (like PFN_WSK_SEND_TO)
were used before they were declared. This patch moves the use after
the definition.
